1. Field of Invention
This invention relates to furniture, and specifically to leisure chairs which enable a user to sit very close to the ground, of the kind which could be ideally used for sitting on while at the beach, on a lawn like at an outdoor concert, or in a home for watching television, reading or working on a laptop computer.
2. Discussion of Prior Art
Over the years, numerous leisure chairs have been developed for enabling people to sit close to the floor. Examples of such chairs include:
U.S. Pat. No. 2,308,410 to Winter discloses folding leisure chairs with and without arms.
Applicant has developed a number of legless leisure chairs and parts thereof including those described in U.S. Pat. Nos. 5,425,567, 5,825,095 and 6,155,647. In U.S. Pat. No. 5,825,095 the armrests are shown approximately at the height of the obtuse angle on the backrest. If, based on preference, the armrests are lowered with respect to the backrest frame and/or the armrests are extended further to accommodate a substantial cushion on the backrest, the chair can tip forward if substantial downward force is exerted on the front of the armrests.
The present invention has two important advantages over the prior art:                1. The chair is more stable, and less likely to tip forward when someone pushes on the front of the armrests to get out of the chair.        2. The backrest pivoting extension enables the lumbar support to move lower as the chair reclines.        3. The adjustment stop provides a simple and very effective reclining mechanism.        
The first advantage is especially important for legless leisure chairs having a substantial cushion on the backrest. In looking for example at the Winter chair with arms, there is reason to believe that the chair would be somewhat unstable if someone pushed on the front of the armrests to get out of the chair. The patent specifically refers on page 2 column 1 line 28 to “there is a liability of the entire frame to tip sideways.” But the applicant, based on working with similar dynamics in legless leisure chairs, suspects there is also a tendency for the chair to tip forward when an occupant pushes on the front of the armrest to get out of the chair. This problem would become substantially greater if the chair had a substantial cushion on the backrest. This is because a cushion moves the body further from the most forward and base point on the backrest frame under the cushion, which would be essentially the pivot point if enough downward force were put on the front of the armrests. Use of a substantial cushion would either reduce the usable length of the armrest, or alternatively would require that the length of the armrest be increased to provide the same usable length of armrest. If the armrest length were increased, the instability of the chair would also increase, because the armrests would extend further in front of the base of the chair.
Additionally, the Winter chair, as well as other legless leisure chairs which recline at a pivot point where the base frame and backrest frame intersect, does not provide for the lumbar support (if there is one, and especially if the backrest is cushioned) to maintain the alignment with the lumbar region of a human user, when the backrest reclines from a generally upright position.
Finally, the adjustment mechanisms such as those on Winter, may be a bit complicated and clumsy to use. Though high quality, and presumably expensive, interlocking adjustment mechanisms such as in reclining car seats seem to hold up well, some legless leisure chairs seem to be made less sturdy interlocking mechanisms that seem to have a high failure rate.
Other prior art includes numerous “legless” chairs with seats of ordinary height, or nearly ordinary height, such as in US D498,065 to David Potter. Such chairs have very different dynamics from chairs such as Winter or legless leisure chairs with a lower seat, including different thigh to calf angles when someone sitting on the chair puts their feet on the floor just in front of the seat cushion. Additionally, according to advertising literature, the referenced chair weighs 87 pounds—significantly more than the legless leisure chairs such as Winter or the present invention. Further, the seat has a space under part of it, as seen from FIGS. 1, 2 and 4, has wheels under it, and the seat has a frame, which appears to be rigidly interconnected with both the armrests and backrest—when not being adjusted for reclining. Thus, the balance of a chair with a seat of ordinary, or nearly ordinary height such as about 16″, is significantly different than a legless leisure chair with a seat of less than about 10″. Not only is the balance different, the experience is different.
Another chair is the iRocker™, which has an open space under the seat cushions and armrests. The height of the armrests on the iRocker™ appear significantly higher than on the current invention, and again similar to chairs with seats of ordinary height, it appears that the weight is very much shifted toward the front. The position of the armrests, seat, and presumed footrest, raise questions in terms of awkwardness in terms of getting out of the chair.
The difference in dynamics in lighter chairs with seats near the floor, present special challenges with regards to balance, safety, ergonomics, convenience, and also with regards to providing optimal backrest alignment when the chair reclines. Though not all of these issues are overtly addressed in this specification, the structure of this invention dovetails with the systems described in applicant's previous patents referenced above.